(a) Field
The invention relates to a liquid crystal display (“LCD”). More particularly, the invention relates to an LCD capable of improving an aperture ratio.
(b) Description of the Related Art
A liquid crystal display (“LCD”) is one of the most widely used flat panel display devices. The LCD generally includes two display panels where a field generating electrode such as a pixel electrode and a common electrode is formed and a liquid crystal layer interposed therebetween.
The LCD generates an electric field in a liquid crystal layer by applying voltage to the field generating electrode, to determine orientations of liquid crystal molecules of the liquid crystal layer and control polarization of incident light, thereby displaying an image.
The LCD also includes a switching element connected to each pixel electrode, and a plurality of signal lines such as gate lines and data lines for applying a voltage to the pixel electrodes by controlling the switching elements.
Among various types of LCDs, a vertical alignment mode LCD, which arranges major axes of liquid crystal molecules so as to be vertical to the display panel when an electric field is not applied, has been widely used due to its high contrast ratio and wide reference viewing angle. Here, the reference viewing angle implies a viewing angle that is 1:10 in contrast ratio, or a critical angle of gray-to-gray luminance reversion.
In order to approximate side visibility to front visibility in the vertical alignment mode LCD, a method of causing a difference in transmittance by dividing one pixel into two sub-pixels and applying different voltages to the two sub-pixels has been proposed. In this case, to differentiate the voltages of two subpixels, the thin film transistor is added and a region for contacting the wiring is increased such that an aperture ratio is decreased.